FIGURE 7.

Influence of Si supply on expression levels of the genes involved in arginine, methionine, and GABA synthesis pathway in leaves of two contrasting tomato genotypes under osmotic stress. (A) relative expression of SlASS, (B) relative expression of SlASL, (C) relative expression of SlMS, (D) relative expression of SlGAD1, and (E) relative expression of SlGAD3. Plants were grown in hydroponic culture and osmotic stress was simulated by applying polyethylene glycol (PEG 6000). Si was provided at 0.75 mM for pre-cultured plants and at 1.5 mM for osmotic stressed plants. Roots and fully expanded leaves from 21-day old plants were harvested 7 days after imposition of osmotic stress. Bars indicate means ± SE. Different letters denote significant differences according to Fischer’s LSD test (p < 0.05; n = 4).